Beginning in 1980(?), led by Jef Raskin, the Macintosh
team at Apple Computer (which included former members of the
Xerox PARC group) continued to develop such ideas in the first
commercially successful product to use a GUI, the Apple
Macintosh, released in January 1984. In 2001 Apple introduced
Mac OS X.

Microsoft modeled the first version of Windows, released
in 1985, on Mac OS. Windows was a GUI for MS-DOS that had
been shipped with IBM PC and compatible computers since
1981. Apple sued Microsoft over infringement of the
look-and-feel of the MacOS. The court case ran for many
years.